'From the Archives': first published in the Digest 16/02/04
Babies start using their feet to explore the world before they use their hands. That's according to James Galloway and Esther Thelen at the Universities of Indiana and Delaware, USA.
Six babies first used their feet to touch toys dangled in front of them when they were on average just 11.7 weeks old, compared with first using their hands at 15.7 weeks. The babies' foot contact wasn't accidental - when the toys were absent, the babies' feet spent significantly less time in the toy-dangling area. This finding was confirmed in a second experiment with 10 infants, in which the toy-to-limb distance (4 inches) was standardised for each baby.
These observations directly violate the classic 'cephalocaudal rule' that states infant movement control progresses in a head-to-toe fashion. They also contradict the idea that in the first months of life, the legs only move in a reflexive, non-purposeful fashion.
The authors argued "the finding that young infants repeatedly aimed their feet to contact the toy suggests the use of supraspinal (i.e. brain) centers for purposeful control much earlier than traditionally envisioned".
Galloway, J.C. & Thelen, E. (2004). Feet first: object exploration in young infants. Infant Behaviour and Development, 27, 107-112.
Did you know? - Jean Piaget also noticed his baby son used his leg to kick a toy. See Piaget, J. (1952). The origins of intelligence in children. New York: International Universities Press.
Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.